gfapi: fix incorrect initialization of upcall syncop arguments

While sending upcall notifications via synctasks, the argument used to
carry relevant data for these tasks is not initialized properly. This patch
is to fix the same.

This is backport of below mainline fix -
> fixes: bz#1718316
> patch url: https://review.gluster.org/#/c/glusterfs/+/22839/
> Signed-off-by: Soumya Koduri <skoduri@redhat.com>

Change-Id: I9fa8f841e71d3c37d3819fbd430382928c07176c
fixes: bz#1720636
Signed-off-by: Soumya Koduri <skoduri@redhat.com>
(cherry picked from commit bc6fd4cfa6ed34de3ffc02e2279fcc713f80f530)

1 files changed, 72 insertions, 37 deletions

diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index 18be736843d..536a7188b3b 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -33,7 +33,7 @@
 
 struct upcall_syncop_args {
     struct glfs *fs;
-    struct gf_upcall *upcall_data;
+    struct glfs_upcall *up_arg;
 };
 
 #define READDIRBUF_SIZE (sizeof(struct dirent) + GF_NAME_MAX + 1)
@@ -4869,12 +4869,28 @@ out:
 }
 
 static int
+upcall_syncop_args_free(struct upcall_syncop_args *args)
+{
+    if (args && args->up_arg)
+        GLFS_FREE(args->up_arg);
+    GF_FREE(args);
+    return 0;
+}
+
+static int
 glfs_upcall_syncop_cbk(int ret, call_frame_t *frame, void *opaque)
 {
     struct upcall_syncop_args *args = opaque;
 
-    GF_FREE(args->upcall_data);
-    GF_FREE(args);
+    /* Here we not using upcall_syncop_args_free as application
+     * will be cleaning up the args->up_arg using glfs_free
+     * post processing upcall.
+     */
+    if (ret) {
+        upcall_syncop_args_free(args);
+    } else
+        GF_FREE(args);
+
     return 0;
 }
 
@@ -4882,13 +4898,29 @@ static int
 glfs_cbk_upcall_syncop(void *opaque)
 {
     struct upcall_syncop_args *args = opaque;
-    int ret = -1;
     struct glfs_upcall *up_arg = NULL;
     struct glfs *fs;
-    struct gf_upcall *upcall_data;
 
     fs = args->fs;
-    upcall_data = args->upcall_data;
+    up_arg = args->up_arg;
+
+    if (fs->up_cbk && up_arg) {
+        (fs->up_cbk)(up_arg, fs->up_data);
+        return 0;
+    }
+
+    return -1;
+}
+
+static struct upcall_syncop_args *
+upcall_syncop_args_init(struct glfs *fs, struct gf_upcall *upcall_data)
+{
+    struct upcall_syncop_args *args = NULL;
+    int ret = -1;
+    struct glfs_upcall *up_arg = NULL;
+
+    if (!fs || !upcall_data)
+        goto out;
 
     up_arg = GLFS_CALLOC(1, sizeof(struct gf_upcall), glfs_release_upcall,
                          glfs_mt_upcall_entry_t);
@@ -4909,33 +4941,51 @@ glfs_cbk_upcall_syncop(void *opaque)
             errno = EINVAL;
     }
 
-    if (!ret && (up_arg->reason != GLFS_UPCALL_EVENT_NULL)) {
-        /* It could so happen that the file which got
-         * upcall notification may have got deleted by
-         * the same client. In such cases up_arg->reason
-         * is set to GLFS_UPCALL_EVENT_NULL. No need to
-         * send upcall then */
-        (fs->up_cbk)(up_arg, fs->up_data);
-    } else if (up_arg->reason == GLFS_UPCALL_EVENT_NULL) {
+    /* It could so happen that the file which got
+     * upcall notification may have got deleted by
+     * the same client. In such cases up_arg->reason
+     * is set to GLFS_UPCALL_EVENT_NULL. No need to
+     * send upcall then
+     */
+    if (up_arg->reason == GLFS_UPCALL_EVENT_NULL) {
         gf_msg(THIS->name, GF_LOG_DEBUG, errno, API_MSG_INVALID_ENTRY,
                "Upcall_EVENT_NULL received. Skipping it.");
         goto out;
-    } else {
+    } else if (ret) {
         gf_msg(THIS->name, GF_LOG_ERROR, errno, API_MSG_INVALID_ENTRY,
                "Upcall entry validation failed.");
         goto out;
     }
 
+    args = GF_CALLOC(1, sizeof(struct upcall_syncop_args),
+                     glfs_mt_upcall_entry_t);
+    if (!args) {
+        gf_msg(THIS->name, GF_LOG_ERROR, ENOMEM, API_MSG_ALLOC_FAILED,
+               "Upcall syncop args allocation failed.");
+        goto out;
+    }
+
+    /* Note: we are not taking any ref on fs here.
+     * Ideally applications have to unregister for upcall events
+     * or stop polling for upcall events before performing
+     * glfs_fini. And as for outstanding synctasks created, we wait
+     * for all syncenv threads to finish tasks before cleaning up the
+     * fs->ctx. Hence it seems safe to process these callback
+     * notification without taking any lock/ref.
+     */
+    args->fs = fs;
+    args->up_arg = up_arg;
+
     /* application takes care of calling glfs_free on up_arg post
      * their processing */
-    ret = 0;
 
+    return args;
 out:
-    if (ret && up_arg) {
+    if (up_arg) {
         GLFS_FREE(up_arg);
     }
 
-    return 0;
+    return NULL;
 }
 
 static void
@@ -4952,24 +5002,10 @@ glfs_cbk_upcall_data(struct glfs *fs, struct gf_upcall *upcall_data)
         goto out;
     }
 
-    args = GF_CALLOC(1, sizeof(struct upcall_syncop_args),
-                     glfs_mt_upcall_entry_t);
-    if (!args) {
-        gf_msg(THIS->name, GF_LOG_ERROR, ENOMEM, API_MSG_ALLOC_FAILED,
-               "Upcall syncop args allocation failed.");
-        goto out;
-    }
+    args = upcall_syncop_args_init(fs, upcall_data);
 
-    /* Note: we are not taking any ref on fs here.
-     * Ideally applications have to unregister for upcall events
-     * or stop polling for upcall events before performing
-     * glfs_fini. And as for outstanding synctasks created, we wait
-     * for all syncenv threads to finish tasks before cleaning up the
-     * fs->ctx. Hence it seems safe to process these callback
-     * notification without taking any lock/ref.
-     */
-    args->fs = fs;
-    args->upcall_data = gf_memdup(upcall_data, sizeof(*upcall_data));
+    if (!args)
+        goto out;
 
     ret = synctask_new(THIS->ctx->env, glfs_cbk_upcall_syncop,
                        glfs_upcall_syncop_cbk, NULL, args);
@@ -4978,8 +5014,7 @@ glfs_cbk_upcall_data(struct glfs *fs, struct gf_upcall *upcall_data)
         gf_msg(THIS->name, GF_LOG_ERROR, errno, API_MSG_UPCALL_SYNCOP_FAILED,
                "Synctak for Upcall event_type(%d) and gfid(%s) failed",
                upcall_data->event_type, (char *)(upcall_data->gfid));
-        GF_FREE(args->upcall_data);
-        GF_FREE(args);
+        upcall_syncop_args_free(args);
     }
 
 out: